Small portable terminals such as mobile phones enabling TV viewing and recording are becoming increasingly popular, and if a user can receive TV waves while moving, or at the user's destination, it is possible to view and record TV broadcasts without restrictions as to location.
In terrestrial digital broadcasting, it is planned to provide a data broadcasting service to such small portable terminals by allocating one of 13 divisions of a channel band (6 MHz) (one segment). This data broadcasting service is called partial reception broadcasting. The amount of information transmitted in one segment is extremely small, and program information and so forth for only ten programs at the most can be included. PSI (Program Specific Information) and SI (Service Information) are known as program information. PSI is information necessary for selecting a desired program, while SI comprises various kinds of information stipulated to make program selection more convenient, including information related to EPG (Electronic Program Guide) such as program names, broadcasting station names, and so forth.
Also, in terrestrial digital broadcasting, when a broadcasting station multiplexes a plurality of data comprising video, audio, and other program information into a single stream, the MPEG protocol MPEG-2 TS (Transport Stream) is used, the multiplexed stream is demultiplexed on the receiving side, and the data prior to multiplexing is obtained. When “TS” alone is referred to below in this Description, this means all partial reception broadcasting data sent by a broadcasting station.
As a plurality of data can be multiplexed in digital broadcasting in this way, unlike analog broadcasting, a plurality of channels can be operated in one frequency band. To avoid confusion and erroneous use, the concept of a channel as used in this Description will be defined here. Channels include physical channels and logical channels, with physical channels also being used in analog broadcasting. A physical channel is a physical frequency assignment channel (hereinafter referred to as “frequency channel”). In terrestrial digital broadcasting, frequency channels from ch13 to ch62 are assigned. A logical channel identifies a plurality of program schemes (hereinafter referred to as “services”) within a frequency channel, and is called a service channel. Such frequency channels and service channels are referred to as channels generically.
The above-described frequency channels are assigned one-touch button numbers on a remote controller or the like for easy identification, these numbers being called remote controller numbers. When channel selection (station selection, tuning) is performed by means of a remote controller number, a main service called “primary service” is selected from among a plurality of service channels included in one frequency channel. A number that is calculated from this remote controller number and the service channel value, whereby a user directly specifies a service within a frequency channel, is called a 3-digit number.
For reference, channel definitions are shown conceptually in FIG. 1. In FIG. 1, a TS is composed of three services and program information comprising PSI information and SI information, service ID: D9A0 (primary service) performs general broadcasting, service ID: D9A1 performs English broadcasting, and service ID: D9A2 performs data broadcasting, with programs A through F being broadcast by these services. An example is shown in which the frequency channel is ch21, the remote controller number is 8, the 3-digit numbers are 681, 682, and 683, and the service IDs are D9A0, D9A1, and D9A2.
Generally, with a non-portable TV recording apparatus, if a remote controller number, recording start time, and recording end time are set in recording preselection, a desired program can be recorded. In contrast, with a portable TV recording apparatus, if recording preselection is performed in a particular broadcast area, and the portable TV recording apparatus moves to another broadcast area before the recording start time, it may not be possible to record the desired program even though a remote controller number, recording start time, and recording end time are set in recording preselection.
Thus, the invention disclosed in Patent Document 1 was devised. FIG. 2 is a block diagram showing the configuration of a portable TV recording apparatus 10 described in Patent Document 1. In this drawing, the current location of portable TV recording apparatus 10 is detected by an extension module 11 provided with a GPS (Global Positioning System) function. Then portable TV recording apparatus 10 makes an inquiry to a program information server 14 from a communication section 12 via a public circuit 13, receives a supply of program information from program information server 14 that holds program information comprising areas in which programs are broadcast, program IDs, channel numbers, broadcast start times, and broadcast durations, determines whether or not broadcast channel information and broadcast time information at the current location differ from those at the time of preselection, and if they differ, updates the preselection information. If a preselected program is not broadcast at the current location, the preselection-time program is recorded by a VTR 15.
By this means, a preselected program can be recorded dependably even if a portable TV recording apparatus moves beyond a broadcast area between the time of preselection and the recording start time. Patent Document 1: Unexamined Japanese Patent Publication No. 2004-23111